I have a similar problem on my Ford truck. First step is to make sure the u-joints have no play. They should have absolutely no play at all that you can notice by applying twisting force with your hands.
After that, as posted above, lubing the slip joint definitely helps, but doesn’t entirely solve it in my case. I don’t remove the drive shaft though, there’s a lube fitting on slip joint so I just use that. I think it might work a little better to remove the drive shaft for this, so I’d have access to the entire length of the spline. I’ll try that next time. The other thing that seems to help is to add some friction modifier to the differential fluid. This makes the clutches in the limited slip differential more slippery. Otherwise those clutches can grab and cause clunking noises.
Other potential causes, it sounds you’ve probably already addressed those: play between the pinion and the ring gear; play between the rear axles and the differential side gears. Play in the transmission or transfer case (if 4WD) could cause it too.
Another less likely possibility, the entire rear axel is subjected to a twisting force during accelerations and decelerations. The truck’s designers know about this of course, and counteract it w/various methods. So perhaps one of those methods isn’t working b/c something fell off or is loose that otherwise would counteract the twisting force. The link below might be helpful.